给你个工程自己看...
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运行后可以看到自己...
点按钮保存到c:\1.bmp
Private Const WS_CHILD = H40000000
Private Const WS_VISIBLE = H10000000
Private Const WM_CAP_START = H400
Private Const WM_CAP_DRIVER_CONNECT = WM_CAP_START + 10
Private Const WM_CAP_SET_SCALE = WM_CAP_START + 53
Private Const WM_CAP_SET_PREVIEWRATE = WM_CAP_START + 52
Private Const WM_CAP_SET_PREVIEW = WM_CAP_START + 50
Private Declare Function capCreateCaptureWindowA Lib "avicap32.dll" ( _
ByVal lpszWindowName As String, _
ByVal dwStyle As Long, _
ByVal x As Long, ByVal y As Long, ByVal nWidth As Long, ByVal nHeight As Integer, _
ByVal hWndParent As Long, ByVal nID As Long) As Long
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Integer, ByVal lParam As Long) As Long
Private Sub Form_Load()
'建立采集窗口（不显示窗口，处理后显示到PIC控件）
uwndc = capCreateCaptureWindowA("", WS_VISIBLE Or WS_CHILD, 0, 0, 320, 240, Me.hWnd, 0)
'连接
SendMessage uwndc, WM_CAP_DRIVER_CONNECT, 0, 0
'Scale开
SendMessage uwndc, WM_CAP_SET_SCALE, True, 0
'显示刷新MS
SendMessage uwndc, WM_CAP_SET_PREVIEWRATE, 40, 0
'用予览方式显示(特殊需要，不显示予缆）
SendMessage uwndc, WM_CAP_SET_PREVIEW, True, 0
End Sub
上述代码就可以实现 但是要注意相应的控件是否存在 不存在的 你自己画出来
这个方法没问题。
win8.1，我用网上的方法，有时也有黑屏现象，但多试几次就好了。有时还会弹出要选择摄像头，选择确认、取消、应用都是黑屏。